To provide a carboxymethyl cellulose and a salt thereof.

There are provided a carboxymethyl cellulose and a salt thereof, excellent in dispersion to water, which show 80 wt.% or more in the proportion of particles having a particle size of 177 μm or less, wherein the bulk specific gravity is 600-900 g/l, the angle of repose (as measured by the gradient method) is 55 or less, and the surface area of the whole particles (as measured by the Kr adsorption method) is 0.3 m2/g or less.